It is well known to utilize solar energy for purposes of heating water in a system which relies upon the tendency of water to stratify according to temperature so as to achieve natural circulation. Natural circulation solar water heaters of the prior art employ a rigid solar absorber surface consisting of a plurality of fluid conducting passages arranged in a plane disposed toward the sun and connected by inlet and outlet manifolds, the latter elevated above the former. A storage tank is suspended near or above the upper or outlet manifold to provide a reservoir into which the heated water rises. Cold water is introduced into the lower or inlet manifold rises through the system as it is warmed in the absorber and the warmed water is withdrawn from the storage tank on demand. A return pipe circulates the water from the upper to the lower manifold. Rigid tubes are commonly employed for the absorber, as well as highly wetted rigid plastic with numerous closely spaced conducting channels. In any event the typical prior art rigid absorber is relatively heavy and bulky and is difficult to handle during shipment and storage.
It is the principal object of the present invention to provide a solar water heater which operates on the principle of natural circulation but which has none of the disadvantages of inefficient space utilization characterizing prior art assemblies.